:root{
  /* background gradient stops */
  --bg-1: #000000;
  --bg-2: #2b2b2b;
  --bg-3: #888888;

  /* black bars */
  --bar-color: #000000;
  --bar-height: 56px;
  --bar-thin: 28px;
  --bar-border-color: rgba(255,255,255,0.9);

  /* white borders / cards */
  --card-bg: rgba(255,255,255,0.03);
  --card-padding: 12px 18px;
  --card-radius: 6px;

  /* tooltip */
  --tt-bg: rgba(0,0,0,0.92);
  --tt-color: #ffffff;
  --tt-border: rgba(255,255,255,0.9);
  --tt-padding: 8px 10px;
  --tt-radius: 6px;
  --tt-font-size: .9rem;
  --tt-offset: 10px;
}

/* page background */
html,body{
  height:100%;
}
body{
  margin:0;
  min-height:100vh;
  background: linear-gradient(180deg, var(--bg-1) 0%, var(--bg-2) 50%, var(--bg-3) 100%);
  color: var(--tt-color);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  line-height:1.4;
}

/* black bars: horizontal */
.black-bar{
  background: var(--bar-color);
  border: 1px solid rgba(255,255,255,0.06);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.04);
  color: inherit;
}
.black-bar.full{
  width:100%;
  height: var(--bar-height);
  border-bottom: 2px solid var(--bar-border-color);
  display:block;
}
.black-bar.thin{
  height: var(--bar-thin);
  padding: 6px 12px;
  border-radius: 4px;
  border: 2px solid var(--bar-border-color);
  display:inline-block;
}

/* vertical side bars */
.side-bars { position:relative; }
.black-bar.side{
  position:fixed;
  top:0;
  bottom:0;
  width: var(--bar-thin);
  height:100vh;
  border-left: 2px solid var(--bar-border-color);
  border-right: 2px solid rgba(255,255,255,0.02);
  z-index:40;
}
.black-bar.side.left{ left:0; box-shadow: inset 1px 0 0 rgba(255,255,255,0.03); }
.black-bar.side.right{ right:0; box-shadow: inset -1px 0 0 rgba(255,255,255,0.03); }

/* white bordered cards & elements */
.white-border, .white-card{
  background: var(--card-bg);
  border: 2px solid var(--bar-border-color);
  padding: var(--card-padding);
  border-radius: var(--card-radius);
  display:inline-block;
  color: var(--tt-color);
  backdrop-filter: blur(2px);
}

/* tooltip system (works on any inline element with class .tooltip and attribute data-tooltip) */
.tooltip{
  position:relative;
  cursor:help;
  outline:none;
  text-decoration:underline dotted rgba(255,255,255,0.2);
}
.tooltip::after{
  content: attr(data-tooltip);
  position:absolute;
  left:50%;
  transform:translate(-50%, calc(var(--tt-offset) * 0.6));
  top: calc(100% + var(--tt-offset));
  background: var(--tt-bg);
  color: var(--tt-color);
  border: 1px solid var(--tt-border);
  padding: var(--tt-padding);
  border-radius: var(--tt-radius);
  font-size: var(--tt-font-size);
  white-space:nowrap;
  z-index:1000;
  opacity:0;
  pointer-events:none;
  transition:opacity 160ms ease, transform 160ms ease;
  box-shadow: 0 6px 18px rgba(0,0,0,0.5);
}

/* small arrow */
.tooltip::before{
  content:"";
  position:absolute;
  left:50%;
  transform: translateX(-50%) rotate(45deg);
  top: calc(100% + (var(--tt-offset) - 6px));
  width:10px;
  height:10px;
  background: var(--tt-bg);
  border-left:1px solid var(--tt-border);
  border-top:1px solid var(--tt-border);
  z-index:1001;
  opacity:0;
  transition:opacity 160ms ease;
}

/* show on hover/focus */
.tooltip:hover::after,
.tooltip:focus::after,
.tooltip[aria-expanded="true"]::after{
  opacity:1;
  transform:translate(-50%, 0);
}
.tooltip:hover::before,
.tooltip:focus::before,
.tooltip[aria-expanded="true"]::before{
  opacity:1;
  transform: translateX(-50%) rotate(45deg);
}

/* tooltip positions via data-pos attribute (top/right/left/bottom) */
.tooltip[data-pos="top"]::after{
  top: auto;
  bottom: calc(100% + var(--tt-offset));
  transform: translate(-50%, calc(-1 * var(--tt-offset) * 0.6));
}
.tooltip[data-pos="top"]::before{
  top: auto;
  bottom: calc(100% + (var(--tt-offset) - 6px));
}
.tooltip[data-pos="right"]::after{
  left: calc(100% + var(--tt-offset));
  top:50%;
  transform: translate(0, -50%);
}
.tooltip[data-pos="right"]::before{
  left: calc(100% + (var(--tt-offset) - 6px));
  top:50%;
  transform: translateY(-50%) rotate(45deg);
}
.tooltip[data-pos="left"]::after{
  left: auto;
  right: calc(100% + var(--tt-offset));
  top:50%;
  transform: translate(0, -50%);
}
.tooltip[data-pos="left"]::before{
  left: auto;
  right: calc(100% + (var(--tt-offset) - 6px));
  top:50%;
  transform: translateY(-50%) rotate(45deg);
}

/* responsive tweaks */
@media (max-width:640px){
  :root{ --bar-height:48px; --bar-thin:20px; --tt-font-size: .85rem; }
  .black-bar.side{ display:none; }
}